~
If you have unlimited free energy, you don’t have to have 1 million ASICs to launch a 51% attack. You would only need one giant ASIC. Yes. It will be expensive. But, the return on investment is much higher. ~
Apart from taking into consideration what stompix said about "one giant ASIC", I think you should still watch that 2 minutes video,
Andreas Antonopoulos - 51% Bitcoin Attack , I was talking about earlier in this thread.
There will be no return! The attackers will just lose huge money, that's all.